Oneplus announced the release of OxygenOS 11.1.1.1 based on Android 11 with a September 2021 security patch via OTA for Oneplus 6T. Initially, The OTA will be received by few users of Oneplus 6T randomly. After making sure that there are no critical bugs, then the rest of the Oneplus 6T started to get the update.
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The Oneplus 6T is released in the year 2018, November 1st with the Android 9(Pie) operating system(OS).

Source: Oneplus Community
| Android OS | Update | Release date/status | Estimated time |
| Android 9 Pie | Out-of-the-box | November 2018 | Nil |
| Android 10 | First update | December 2019 | 3 months |
| Android 11 | Second update | August 2021 | 11 months |
| Android 12 | Third update | Eligible - Not Confirmed | Unconfirmed |
This device has received two major OS update, and unlike Its younger version Oneplus 6 which was launched Android 8.1 Oreo, this device came with Android 9 Pie and its highly unlikely that this device will get Android 12. Because its the new Oneplus right now.
once the update is available on your device, then you can head over to Settings >> About Phone >> Software Update section to update your Oneplus 6T with the latest September 2021 security patch update with OxygenOS 11.
Firstly the update is only available for few users of Oneplus 6T after ensuring that there are no critical bugs, the remaining users get updates.
Note: Backing up data is essential, as the update may encounter bugs and there might be a chance of data loss.
For more OnePlus Android updates please download our android app – available on the Play Store